NATIONAL RENEWABLE ENERGY CENTRE

Biomass Torrefaction Integration in Coal IGCC/XTL: technical possibilities, concept advantages, synergies and

development requirements8th International Freiberg Conference on IGCC & XtL Technologies

12-16 June 2016, Cologne, Germany

í n d i c e

1. Introduction to CENER 2. CENER Capacities and Experience in Torrefaction3. Biomass supply chains for IGCC and XTL4. Torrefaction reactor integration in IGCC/XTL plant5. Conclusions

1. Introduction to CENER

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01 Introduction to CENER

Vision

Mission

To be a research centre of excellence in therenewable energies field with international outreach.

To generate knowledge in the renewable energy fieldand to transfer it to the industry in order to boostsustainable energy development.

Mission and Vision

Areas

WindBiomassSolar PhotovoltaicSolar ThermalEnergy Grid IntegrationEnergy in Building

Infrastructures

01 Introduction to CENER

HeadquartersSarriguren

Second Generation Biofuels Centre Aoiz

Wind Test LaboratorySangüesa

Offices:Sevilla

Experimental Wind FarmAlaiz

Microgrid, Sangüesa

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1. Biomass Torrefaction:� Solid biofuel development from torrefied biomass� Torrefied products development

2. Alternative Raw Materials Pellets Development� Development of additives to improve press productivity� Development of additives to improve combustion behaviour

3. Sustainability Studies� GHG & Energy Balances � Development and Application of Sustainability Schemes to Advanced

BioProducts

4. Bio-products from Sugar Platform� Optimization of pre-treatment/fractionation process for lignocellulosic materials � Development and optimization of fermentative processes

5. Biomass gasification� Feeding system development and optimization for alternative raw materials� Analysis of ashes and inorganic compounds behaviour

01 Introduction to CENERBiomass Department Strategic Research Lines

2. CENER Capacities and Experience in Torrefaction

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02. Overview of CENER Capacities and Experience in Torrefaction Main milestones

• 2006-2007: Feasibility study biomass torrefaction for cofiring applications

• 2007-2008: Evaluation and selection of technologies. Laboratory and bench scale testing.

• 2008-2009: Design and construction of pilot plant. Pilot plant commissioning..

• 2010: Modification in the pilot plant. Transfer of the pilot plant from Noain to CB2G in Aoiz.

• 2011: Beech woodchips torrefaction. First pelletization tests.

• 2012-2015: SECTOR project (www.sector.eu): CENER is leading partner of agriculturalbiomass torrefaction activities.

• 2012: Torrefaction and pelletization of beech and pine. Torrefaction reactor modeldevelopment 1.0.

• 2013: Loose chopped straw, pine and polar torrefaction and pelletization. Production of ahigh quality torrefied straw pellet batch. Development of torrefied biomass self-heatingcharacterization methodology.

• 2014-2015: Torrefaction and pelletization of eucalyptus, paulownia, olive tree pruning andcereal straw pellets. Torrefaction reactor model development 2.0.

• 2015-2016: Optimization and improvement of torrefied biomass pelletization.

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• Torrefaction pilot plant with a production capacity of 150 - 350kg/h based on a internally rotating shaft indirectly heated reactorusing thermal oil (250-300ºC):

• Very flexible regarding raw material particle sizedistribution (0,25-40 mm) and bulk density (50-500 kg/m3)including agricultural biomass like straw.

• Excellent mixing and agitation minimizing internaltemperature gradients, easy temperature control, beingable to cope with feedstock with exothermal heat ofreaction, producing a extremely homogeneous product.

• Raw materials tested:• Beech woodchip• Pine woodchips• Loose chopped straw• Poplar woodchips• Eucalyptus woodchips• Paulownia woodchips• Olive tree pruning woodchips• Cereal straw pellets• Compost

Torrefaction pilot plant02 Overview of CENER Capacities and Experience in Torrefaction

Feedstock flexibility: raw material/product dp-density operative window

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Pelletization pilot plants

• Pelletizing pilot plant with a production capacity of200-700 kg/h:• Hammer mill: screen size 2-12 mm• Mixer with 1 m3: moisture content adjustment

and additive feeding• Mill press of 30 kW:

• Ad Hoc die designs: pellets diameter,compression ratio, number of holes,etc…

• New roller designs

02 Overview of CENER Capacities and Experience in Torrefaction

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03. Torrefied biomass pelletizationExamples of materials processed in the pilot plants

Beech woodchips Pine woodchips Chopped straw Poplar woodchips

+ eucalyptus, paulownia, olive tree pruning …

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Parameter Beech Pine Straw Poplar Eucalyptus

Torrefaction degree% drybasis

13-22 14-23 13-22 14-23 25

Bulk density kg/m3 (ar) 620-710 660-680 620-710 660-680 680-700

Durability % 92.6-98.2 96.4-97.1 92.6-98.2 96.4-97.1 92,5-98,4

fines % 0.05-0.6 0.06-0.09 0.05-0.6 0.06-0.09 0,17-0,18

Moisture % (ar) 5.1-8.3 7.0-7.7 5.1-8.3 7.0-7.7 5,1-5,3

GCV GJ/t (daf) 19.3-19.6 20.1-21.1 19.3-19.6 20.1-21.1 21.1

C % (daf) 50.5-51.5 53.3-55.5 50.5-51.5 53.3-55.5 57,7

H % (daf) ~6.2 6.0-6.1 ~6.2 6.0-6.1 6,0

N % (daf) 0.58-0.77 0.12-0.16 0.58-0.77 0.12-0.16 0,60

Ash % (db) 4.8-6.0 1.6 4.8-6.0 1.6 6,9

Volatile % (db) 73.6-74.8 73.1-77.0. 73.6-74.8 73.1-77.0. 62,9%

03. Torrefied biomass pelletizationExample of torrefied biomass pellets properties

Torrefaction reactor modeling

• A number of perfectly mixed reactors in series. The products output from one stage will be the input of the next.

• Heat transfer coefficient is calculated with a model based on biomass physical properties

• The torrefaction process is according the kinetic model from Di Blasi Lanzetta

• Kinetic parameters are obtained by thermogravimetricanalysis of studied biomasses.

• Heat of reaction parameters are obtained by Differential scanning calorimetry (DSC) of studied biomasses

• Biomass particles are considered as isothermal. Intra-particle temperature profiles are neglected.

• Gas-solid heat transfer is neglected• For each stage mass balance and energy balance equations

are solved• Model calculates:

conversion, temperature profile, gas temperatureand heat demand of the reactor

Model is used for reactorupscaling and for techno-economic case studies

02 CENER Capacities and Experience in Torrefaction

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0 10 20 30 40

Wei

ght

loss

sim

ulat

ed (%

daf

)

Weight loss calculated (% daf )

Pine

Beech

Straw - choped

Poplar

Eucalyptus

Paulownia

Straw pellets

Olive - Prunings

Compost

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0 20 40 60 80A

vera

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imul

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-2K

-1)

Average U calculated (W m-2 K-1)

Pine

Beech

Straw - choped

Poplar

Eucalyptus

Paulownia

Straw pellets

Olive - Prunings

Compost

Model validated in 30 pilot tests with 9 very different feedstock

02 CENER Capacities and Experience in Torrefaction

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Techno-economical models

• Techno economical models developed by CENER for up-scaling studies:

• Kinetic and thermodynamic reaction model, heat transfercoefficient model � kinetic parameters, heat of reaction andheat transfer coefficient

• Reactor flow and heat exchange model � conversiondegree and reactor heat demand

• Product transformation model � Product characteristics:LHV, elemental composition, volatile content

• Integrated process mass and energy balance model� required process inputs and efficiency

• Production cost economical model

� Production cost optimization studies� Industrial process up-scaling� Techno-economical studies

3. Biomass supply chains for IGCC and XTL

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� TORREFACTION IS THE KEY

� For most biomass materials torrefaction is the key enabling technologyneeded tofeed them to Pressurized Entrained Flow Gasifiers (PEFG).

�A short commercial scale test (1200 tons)was already successfully carried out inWillem Alexander Centrale Buggenum by Vatenfall.

3. Biomass supply chains for IGCC and XTL

MAIN CONCLUSION:• No big technical

challenges were observed during conveying, sluicingand milling of the 70% mixture .

.

Source: First experiences from large scale co- gasification tests with refined biomass fuels Presentation at Central European Biomass Conference International workshop: Torrefaction of biomass 17th January 2014, Graz, Austria Nader Padban, Vattenfall R&D Date: 17th January 2014

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�USUAL SUPPLY CHAIN CONCEPT = LACK GUARANTEE OF SUPPLY

�The usual supply chain conceptis based in several torrefaction plants that producedtorrefied pellets which are transported to the IGCC/XTL plant in another location. In thisconcept there is a problem of guarantee of supplysince there are very few potentialsuppliers with small capacity

�One 500 MW PEFG fed with 25% torrefied biomass consumes aprox. 160.000 tpa.Present worldwide installed capacity in operation aprox 235.000 tpa(Source: Statusoverview of torrefaction technologies A review of the commercialization status ofbiomass torrefaction 2015 IEA Bioenergy)

�It is the typical chicken –egg problem: without a demand (take off agreements) it isnot possible to set up industrial torrefaction production plants and on the other handwithout a portfolio of accredited suppliers the utilities do not make the necessary changesfor new fuels.

3. Biomass supply chains for IGCC and XTL

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���� PROPOSAL: ALTERNATIVE SUPPLY CHAIN CONCEPT

�In parallel white pellets market is developing quite fastdue to co-firing and heatingmarket demand in Europe.�Some coal power plants are being converted to 100% Biomasshandling largeamounts of pellets with well-developed logistic systems.�The supply market size accounts 28 millions of tonsand is increasing quick at rate of2-3 million tons per year. Therefore long term supply seems to be guaranteed.

3. Biomass supply chains for IGCC and XTL

4. Torrefaction reactor integration in IGCC/XTL plant

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Conceptual integration.04. Torrefaction reactor integration in IGCC/XTL plant

� Integration/retrofiting has not great technical challenges:

Source: Vatenfall modified by CENER

� Upstream pellet cover storage andtransfer system will be needed

� Torrefaction is a relatively isolatedupstream process packageconsisting of:� Pellets feedingsystem� Torrefaction reactor� TorGas combustionchamber� Heat recovery

� Hot torrefied product is trasnfereddirectly to the coal mill

� Hot flue gases from the heatrecovery are fed to the mill for coaldrying

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Mass and energy balance.04. Torrefaction reactor integration in IGCC/XTL plant

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Mass and energy balance.04. Torrefaction reactor integration in IGCC/XTL plant

�Main advantages of the supply chain concept:

� Raw material supply could be guaranteed

� Using pellets torrefaction reactor size is comparatively smallerfor the samemass flow production rate.

� Higher thermal efficiency due to heat losses reduction. Larger capacity andsmarter heat integration.

� N2 for inertization is available on site at low cost

� High economies of scalecould be reached.

� Safety issues related with torrefied pellets handle due to the higher dust formation(lower durability) are avoided

� Torrefied biomass pelletization is avoided, which could be energy intensive.

�Disadvantages:

� Investment is needed. Loss of flexibility

� Logistic costs are increased due to the lower energy density

5. Conclusions

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.5. Conclusions

� For most biomass materials torrefaction is the key enabling technology forPressurized Entrained Flow Gasifiers.

� In the short-medium term it seems to be difficult to warranty torrefied pelletssupply since the potential demand for IGGC/XTL plants is much higher than presentproduction capacity.

� White pellet market is developing fast and supply is warranted

� Using white pellets and torrefied them on site could be a good solutiontoovercome this market barrier

� Integration of white pellets torrefaction in the IGCC/XTL plant seems to berelatively simple and feasible.

� Identified advantages could overcome disadvantages at least in the short termuntil a wide portfolio of torrefied pelets supplier is developed

�Pilot, demo and flagship torrefaction plant integration with PEFG should be promotedfor market implementation of this supply chain concept.

ACKNOWLEDGEMENTS

The construction of the CB2G has been funded by the Government of Navarre (Navarre Plan2012), the Spanish Ministry of Science and Innovation (National Program for Scientific-Technological Infrastructures) and the European Fund for Regional Development (FEDER)

Contact: Javier Gil: jgil@cener.com

www.cener.com